>How would you do a fresh reinstall of Windows Explorer?
>

If a reinstall of Windows Explorer was indeed necessary, you'd pretty much need to reinstall Windows.

Have you checked for a virus? Have you downloaded and run an anti-spyware program, such as AdAware?

What version of Windows are you running? If it is XP, try to do a system restore...you can restore the system to a previous restore point. Don't remember exactly where it is; look under Start|Accesseries|System Tools.